docs: def _wait_for_disk_threads(self, terminate):
          # type: (Downloader, bool) -> None
          """Wait for disk threads
          :param Downloader self: this
          :param bool terminate: terminate threads
          """
          if terminate:
              self._download_terminate = terminate
          for thr in self._disk_threads:
              blobxfer.util.join_thread(thr)